Final answer:
The provided information is insufficient to calculate the single event standard deviation from an Xbar R chart as the average range (R-bar) or other necessary parameters are not given. Additional data or context is needed to complete the calculation.
Step-by-step explanation:
The question pertains to the use of an Xbar R chart, which is a statistical quality control tool used to monitor the mean of a process over time. Given that the upper control limit (UCL) is 105, the mean of the process (X double bar) is 65, and the sample size (n) is 4, we need to calculate the value of the single event standard deviation (s). The formula linking the control limits of the mean chart to the process mean (X double bar) and the standard deviation is usually given as UCL = X double bar + A2 * R-bar, where R-bar is the average range of the samples and A2 is a factor dependent on the sample size. However, since the value of R-bar is not provided, we cannot calculate the single event standard deviation directly from the information given.
Due to the missing information, it is recommended to refer to additional data or the context in which the question was asked to obtain R-bar or other necessary parameters to calculate the single event standard deviation.